Closure assembly for packaging bags

ABSTRACT

The present invention concerns a closure assembly comprising two complementary elements ( 100, 200 ) supported by respective webs, characterized by the fact that said two complementary elements ( 100, 200 ) are supported by primary webs ( 160, 260 ) coextruded with said two complementary elements ( 100, 200 ) and that the closure assembly also comprises secondary webs ( 170, 270 ) coextruded with said two complementary elements ( 100, 200 ), designed to be connected to the walls ( 10, 20 ) of the bag and which are connected to the primary webs ( 160, 260 ) at respective articulations ( 172, 272 ) formed by extrusion and situated in line with connection zones ( 102, 202 ) of a pair of complementary closure elements ( 100, 200 ) on the primary webs ( 160, 260 ) and additional rows of complementary elements ( 100   b,    200   b;    100   c,    200   c ) supported by the primary webs ( 160, 260 ) of at least one side of the articulation zones ( 172, 272 ).

The present invention concerns the field of packaging bags.

More specifically, the present invention concerns the field of packaging bags comprising closure means in the form of complementary sections.

Many packaging bags and many closure assemblies have already been proposed to that end.

Most of the known closure assemblies to that end comprise two complementary elements 100, 200, for example of the male/female type or the velvet/hooks type or the complementary hooks type, supported by respective support webs 150, 250, as illustrated in the appended FIG. 1. Such support webs 150, 250 can be attached on the films making up the bag or made by extrusion with these films.

For many years the desire has been expressed to have closure assemblies corresponding to the aforementioned principle, but having an opening difficulty under the effect of a stress coming from inside the bag. Such a problem aims to avoid untimely opening of bags equipped with such closure assemblies.

In 1965 were thus proposed, in document U.S. Pat. No. 3,347,298, closure assemblies of the type illustrated in the appended FIG. 2 according to which the female element 200 has a widened base 201 on its outer side, in order to make opening easier under the effect of an external stress than under the effect of an internal stress. These closure assemblies did not, however, experience real industrial developments.

In 1981, in document U.S. Pat. No. 4,430,070, it was proposed to realize closure assemblies of the type illustrated in the appended FIG. 3 by fastening films 10, 20 on pre-extruded complementary elements 100, 200. More specifically, according to this document the films 10, 20 are only fixed on a portion of the surface of the complementary elements 100, 200, in order to generate a so-called hinge effect intended to allow relative pivoting between the films 10, 20 and the complementary elements 100, 200, under the stress of the pressure inside the bag, in order to make opening of the bag under this stress more difficult. The effectiveness of such closure assemblies was not, however, clearly demonstrated. Document U.S. Pat. No. 4,430,070 itself also proposes, in its FIGS. 5 and 6, alternative embodiments according to which the films 10, 20 would be welded on the entire surface of one of the closure elements 100, 200, then prohibiting the hinge effect for the concerned element. The closure assemblies of the type illustrated in FIG. 3 also did not experience real industrial developments. Without explaining it completely, it was considered that these closure assemblies were not completely satisfactory inasmuch as the hinge effect remains random due to the difficulty of precisely locating the connection zone between the films 10, 20 and the closure elements 100, 200 by dielectric closure. If indeed the connection zone covers the entire surface of the closure elements 100, 200, due to the surface state of these means at the exit of the fastening station proceeding by dielectric closure, a hinge effect is not obtained. If on the contrary the connection zone between the films 10, 20 and the closure elements 100, 200 is too weak, the assembly has insufficient strength and can lead to untimely breaks.

In 1988 in document FR-A-2628067 were proposed closure assemblies of the type illustrated in the appended FIG. 4. FIG. 4 more precisely illustrates the mouth of a resealable bag known from that document. The arrangements illustrated in FIG. 4 aim to limit the risk of pressure inside the bag tending to separate the closure elements 100, 200.

In the appended FIG. 4, we see the two main walls 10, 20 of a bag, at the mouth thereof. We also see, in the appended FIG. 4, a closure assembly comprising two complementary closure elements 100, 200 supported by respective webs 150, 250 fixed on the films 10 and 20, respectively.

More specifically, the fixing zones of the support webs 150, 250 on the films 10 and 20 are referenced 152 and 252.

One will note upon examining FIG. 4, that the zone 152 for fixing the support web 150 on the film 10 is not superimposed on the male element 100, but offset relative thereto. Alternatively this could involve offsetting the zone 252 for fixing the support web 250 on the film 20 in relation to the female element 200.

Thus, the web 150 forming support for the male element 100 is articulated on the film 10 at the fixing zone 152. It is indicated in document FR-A-2628067 that owing to this arrangement, the pressure inside the bag leads a possible pivoting of the support web 150 at the hinge zone formed by its fastening 152, without risk of separation of the closure elements 100 and 200.

In FIG. 5 we have illustrated an alternative embodiment also described in document FR-A-2628067 according to which the two support webs 150, 250 are fixed on the respective films 10 and 20 at localized zones 152, 252 not superimposed with the closure elements 100 and 200.

The present invention now aims to improve the prior art by proposing new means making it possible to limit the risk of untimely opening of the closure means under the effect of pressure inside the bag. The invention thus in particular aims to limit the risk of opening during handling or during storage or stacking of bags.

The aforementioned aim is achieved in the framework of the present invention owing to a closure assembly including two complementary elements supported by respective webs, characterized by the fact that said two complementary elements are supported by primary webs coextruded with said two complementary elements and that the closure assembly also comprises secondary webs coextruded with said two complementary elements, designed to be connected to the walls of the bag and which are connected to the primary webs at respective articulations formed by extrusion and situated in line with the connection zones of a pair of complementary closure elements on the primary nets and additional rows of complementary elements, supported by the primary webs of at least one side of the articulation zones.

As we will explain below, the preceding features make it possible to prevent the pressure inside the bag from separating the sections. In fact, owing to these features pressure inside the bag leads to traction exerted by the secondary webs, which tends to strengthen the hooking of the complementary closure elements.

Moreover, the realization of the entire closure assembly comprising the closure elements, the primary webs and the secondary webs, by extrusion, makes it possible to localize the articulation zones completely reliably.

When one wishes to allow easy opening of the bag from the outside thereof, provided, on the closure assembly, are open auxiliary webs connected at least semi-rigidly to the primary webs, respectively. On the contrary, when one wishes to make opening quasi-impossible from the outside of the bag, no such auxiliary opening webs are provided or only auxiliary webs flexibly articulated on the primary webs.

The present invention also concerns the bags equipped with a closure assembly of the aforementioned type.

Other characteristics, aims and advantages of the present invention will appear upon reading the following detailed description, and in light of the appended drawings, provided as non-limiting examples and in which:

the appended FIG. 1 previously described diagrammatically illustrates a closure device or a mouth of a bag according to the prior art,

the appended FIGS. 2, 3, 4 and 5 previously described diagrammatically illustrate closure devices or mouths of bags according to alternative embodiments known from the prior art, in particular from documents U.S. Pat. No. 3,347,298, U.S. Pat. No. 4,430,070 and U.S. Pat. No. 4,817,188,

FIG. 6 is a partial cross-sectional view of a closure device designed to equip the mouth of a bag, according to a first embodiment of the present invention,

FIGS. 7 and 8 respectively illustrate the stresses exerted on such a closure assembly during an opening attempt from the outside on one hand and under the effect of the pressure inside the bag on the other,

FIG. 9 illustrates an alternative embodiment of a closure assembly according to the present invention having dissymmetrical complementary elements,

FIGS. 10, 11 and 12 illustrate three other alternative embodiments of a closure assembly according to the present invention,

FIGS. 13 and 14 respectively illustrate a closure assembly according to the present invention connected to the walls of a bag and a closure assembly according to the present invention attached on the walls of a bag,

FIGS. 15 and 16 illustrate two alternative embodiments of a closure assembly according to the present invention provided with an opening indicator,

FIGS. 17 and 18 illustrate two alternative embodiments of a closure assembly according to the present invention equipped with an operating slide,

FIGS. 19 and 20 illustrate two alternative embodiments according to the present invention of a closure device designed to allow difficult opening, both under pressure from inside the bag, and from outside the bag,

FIG. 21 illustrates an alternative embodiment of a closure assembly according to the invention comprising ridges on support webs,

FIG. 22 illustrates an alternative embodiment of a closure assembly according to the invention comprising an additional articulated sealing web,

FIG. 23 illustrates a cross-sectional view of a specific embodiment of a closure assembly according FIGS. 6 and 10 in its principle,

FIG. 24 illustrates an alternative embodiment from FIG. 23,

FIG. 25 illustrates a cross-sectional view of a specific embodiment of a closure assembly according to FIG. 20 in its principle, and

FIGS. 26 and 27 illustrate two alternative embodiments of closure assemblies according to the present invention including additional sealing means.

The closure assembly according to the present invention is realized entirely by extrusion, in thermoplastic material, for example polyethylene- or polypropylene-based.

In the appended FIG. 6, we have illustrated a closure assembly according to the present invention comprising two complementary elements 100 a, 200 a supported by primary webs 160, 260. The respective connection zones of the complementary elements 100 a, 200 a on the primary webs 160, 260, are referenced 102 and 202. According to the non-limiting embodiment of FIG. 6, the complementary elements 100, 200 are made up of elements of the male/female type, with complementary shapes. In their general structure, such male/female complementary elements are well-known by those skilled in the art. They therefore will not be described in further detail below.

Upon examining the appended FIG. 6, one will note that according to the invention the closure assembly also comprises secondary webs 170, 270 designed to be connected to the main walls of the bag. The secondary webs 170, 270 are connected to the primary webs 160, 260 at respective flexible articulations 172, 272 situated in line with the connection zones 102, 202 of the closure elements 100 a, 200 a on the primary webs 160, 260. “Situated in line with the connection zones 102, 202” signifies that the articulations 172, 272 of the secondary webs 170, 270 are placed opposite said connection zones 102, 202, and not above or below them.

According to the embodiment illustrated in FIG. 6, the primary webs 160, 260 extend on either side of the connection zones 102 and 202. The section of the primary webs 160, 260 which extends toward the inside of the bag is referenced 162, 262. The section of the primary webs 160, 260 which extends toward the outside of the bag is referenced 164, 264.

As we will explain below, in order to allow easy opening of this assembly, from the outside, the intrinsic rigidity of the external sections 164, 264 of the primary webs and the rigidity of the connection existing between these external sections 164, 264 of the primary webs and the closure elements 100 a, 200 a, are greater than the rigidity of the articulation connection 172, 272 defined between the secondary webs 170, 270 and the primary webs 160, 260.

Thus the external sections 164, 264 of the primary webs 160, 260 constitute auxiliary opening webs respectively connected at least semi-rigidly to the primary webs 160, 260 allowing easy opening of the bag from the outside thereof.

Even more specifically, as seen in the appended FIG. 6, each of the primary webs 160, 260 supports a plurality of complementary elements 100, 200 capable of engaging. According to the embodiment of FIG. 6, thus provided are three levels of complementary elements 100 a, 200 a, 100 b, 200 b and 100 c, 200 c. This number is not, however, limiting.

Moreover, in FIG. 6 we see that the complementary elements supported by the primary webs 160, 260 are mixed, in the sense that they comprise a first level of complementary element 100 a, 200 a of the male/female type in line with the articulation zones 172, 272 of the secondary webs 170, 270, and two additional levels of complementary elements 100 b, 200 b and 100 c, 200 c of the hooks type, on the inside of the bag in relation to the first level of aforementioned complementary elements 100 a, 200 a.

Aside from the fact that providing several levels of complementary elements makes it possible to strengthen the closure of the bag, one skilled in the art will understand that the use of additional complementary element levels 100 b, 200 b, 100 c, 200 c on the inside of complementary elements 100 a, 200 a situated in line with the articulation zones 172, 272, makes it possible to limit the opening risk of the first level of complementary elements 100 a, 200 a under the internal pressure, by lever arm.

In FIG. 7, we have illustrated the stresses applied on such a closure assembly during an opening attempt from outside a bag.

As seen in FIG. 7, when the upper portions 164, 264 of the primary webs 160, 260, opposed to the internal volume of the bag, are stressed in separation, a pivot P is applied on the primary webs 160, 260 and on the complementary elements 100, 200, tending to separate the complementary elements 100, 200 and consequently disengage them.

One skilled in the art will in fact appreciate, upon compared examination of FIGS. 6 and 7, that in particular when a stress is applied on the upper portion 164, 264 of the primary webs 160, 260, as illustrated in FIG. 7, the accumulated length between the fixing points 102, 202 of the complementary elements 100, 200 on the primary webs 160, 260, passing along the median of the complementary elements 100, 200, is greater than the same distance in the engaged state illustrated in FIG. 6.

The disengagement of the complementary elements 100, 200 illustrated in FIG. 7 is also due to the change of relative positioning of the complementary elements 100, 200 resulting from the stress.

On the contrary in FIG. 8, we have illustrated the stress applied to the closure assembly under the effect of the pressure inside the bag.

As seen in FIG. 8, owing to the flexible articulation 172, 272 of the secondary webs 170, 270 on the primary webs 160, 260, the pressure inside the bag leads to exerting a transverse traction T on the primary webs 160, 260 perpendicular to the mid-plane thereof. This traction tends on the contrary to strengthen the engagement of the complementary elements 100 and 200.

Thus, one skilled in the art understands upon comparative examination of FIGS. 6, 7 and 8 that the closure assembly according to the present invention leads to easy opening when a stress is exerted from the outside as illustrated in FIG. 7 and on the contrary to strengthening the engagement and closure under the effect of the internal pressure as illustrated in FIG. 8.

As illustrated in FIG. 9, if necessary, at least one of the closure means 100, 200 can be dissymmetrical in order to facilitate the deformation and separation of the closure elements when a stress is exerted from the outside and on the contrary to maintain, or even strengthen, the engagement of the elements 100 and 200 under the effect of the pressure inside the bag.

More specifically according to the embodiment illustrated in FIG. 9, the internal branch 204 of the female closure element 200 is thicker and more rigid than its external element 206. Of course other alternative dissymmetries can be considered, including a dissymmetry of each of the two elements 100 and 200.

In FIG. 10 we have shown an alternative embodiment according to which the different complementary elements are all formed by arrowhead elements comprising a foot 110, 210 and a flared tip 112, 212 in convex V toward the opposite primary web 160, 260.

More specifically according to the non-limiting embodiment of FIG. 10, each web 160, 260 supports three arrowhead elements designed to become interlinked with the complementary elements supported by the opposite web. The webs 160, 260 and the complementary elements supported by them are therefore globally symmetrical.

In FIG. 11, we have shown an alternative embodiment according to which the additional levels of complementary elements are replaced by two flanges 120, 220 respectively supported by the internal end of the primary webs 160, 260. Such flanges 120, 220, by maintaining a separation between the support webs 160 and 260, limit the opening risk of the complementary elements 100, 200 by lever arm effect under the effect of the internal pressure. It also strengthens the sealing of the closure assembly by mutual bearing.

FIG. 12 illustrates an alternative embodiment according to which the two flanges 120, 220 are replaced by a single flange 130 supported by the internal end of the primary web 160.

In FIG. 13, we have illustrated an alternative embodiment of sack or bag according to which a closure assembly according to the invention is connected to the main walls 10, 20 of the bag. In FIG. 13 we see two main films 10, 20 making up the bag in a manner traditional in itself. The particular terms for realizing such a hag, in its general structure, will not be described in detail below.

The walls 10, 20 of the bag can be the object of many embodiments. This preferably, as for the closure assembly according to the present invention, involves walls in thermoplastic material, for example polyethylene- or polypropylene-based.

These walls can be single- or multi-layer and single- or multi-material. If necessary, it can be a paper support coated with a layer of thermoplastic material, or a metalized thermoplastic layer.

The bag can be realized using a single sheet folded on itself and welded on three sides or using several sheets, for example two sheets welded together at their edges, preferably along ridges connecting the main walls.

In the appended FIG. 14, we have illustrated an alternative embodiment according to which the bag is realized by supply and welding or sticking of a closure assembly according to the invention on films 10, 20. In FIG. 14, the welding zones of the closure assembly on the films 10, 20 are referenced 12, 22.

Of course, the realization of bags as illustrated in FIGS. 13 and 14, whether with a closure assembly connected on the films 10, 20 as illustrated in FIG. 13 or a closure assembly attached on the films 10, 20 as illustrated in FIG. 14, applies to all of the alternative embodiments of the closure assembly according to the present invention.

In FIG. 15, we have illustrated an alternative embodiment according to which a web or film 140 is provided forming opening indicator which initially connects the free edges of the internal sections 162, 262 of the primary webs 160, 260. One skilled in the art will understand that such a web 140 must be broken upon the first use, i.e. during the first opening of the bag. The breaking of the film 140 makes it possible to visualize that first opening.

The film 140 also makes it possible to strengthen the sealing of the bag.

If necessary the web 140 can include a weak point 142, preferably in its median portion, for example in the form of a less thick zone or a zone in a more fragile material, in order to localize the preferential break line of that web 140.

In FIG. 16, we have illustrated another alternative embodiment of a closure assembly according to the present invention comprising a film or web 144 forming opening indicator and sealing strengthener initially connecting the free edges of the outer sections 164, 264 of the primary webs 160, 260. The operation of such an indicator web 144 remains equivalent to that of the web 140 illustrated in FIG. 15. If necessary, the web 144 can also include a weak zone 146 comparable to that 142 of the web 140.

In FIG. 17, we have illustrated an alternative embodiment of a closure assembly according to the present invention comprising an operating slide 300.

Such a variation is applicable to all of the embodiments according to the present invention.

A slide 300 can in fact be used for all of the alternative embodiments of the closure assembly proposed in the framework of the present invention.

Such a slide 300 is known in itself in its general structure. It will therefore not be described in detail below. It will simply be recalled that in general, such a slide 300 comprises a sole 302 which supports two side webs 304, 306 and a central wall 308 defining between them two non-parallel channels 310, 312 respectively receiving at least the apex of one of the two primary webs 160, 260 of the closure assembly or walls 10, 20. Thus depending on the direction of movement of the slide 300, the latter part stresses the complementary closure elements 100, 200 upon opening and closure, respectively.

Alternatively the embodiment illustrated in FIG. 17 can be completed by a film or web 140 forming opening indicator and sealing strengthener initially connecting the free edges of the inner sections 162, 262 of the primary webs 160, 260 comparable to FIG. 15.

In FIG. 18, we have shown an alternative embodiment of a closure assembly according to the present invention comprising such a slide 300 also covered by a film or web 148 forming an opening indicator. The film 148 overlaps the slide 300 and is connected to the primary webs 160, 260 or to the secondary webs 170, 270, typically at the articulation zones 172, 272. One skilled in the art will understand that this web 148 must be broken during the first use in order to allow access to the slide 300. Preferably to this end the web 148 includes a line of weakness 149 similar to lines of weakness 142, 146.

The alternative embodiments illustrated in FIGS. 19 and 20 correspond to embodiments of closure devices according to the present invention, adapted to make opening difficult both under an internal stress and an external stress, once the device is placed in the closure position.

In FIG. 19 we have illustrated an alternative embodiment which differs from that illustrated in FIG. 6 by the fact that the primary webs 160, 260 are interrupted at articulation zones 172, 272. In other words, according to this variation, no auxiliary opening webs 164, 264 are provided. Those skilled in the art will easily understand that according to this alternative, it is no longer possible to exert an opening stress of the assembly from the outside.

In FIG. 20, we have illustrated an alternative embodiment which differs from FIG. 10 by the fact that additional auxiliary webs 190, 290 are provided oriented toward the outside of the closure assembly. These additional auxiliary webs 190, 290 are also flexibly articulated on the primary webs 160, 260, at articulation zones 172, 272. Thus, when an opening stress is exerted by traction on the additional auxiliary webs 190, 290, a traction is exerted perpendicularly to the primary webs 160, 260 comparable to the illustration of FIG. 8, without risk of opening of the closure device and the bag.

More precisely according to FIG. 20, the primary webs 160, 260 extend on either side of the articulation zone 172, 272 and the closure assembly comprises secondary webs 170, 270 and additional auxiliary webs 190, 290 all flexibly articulated in 172, 272 on the primary webs 160, 260.

It will also be recalled that according to the embodiment illustrated in FIG. 20, not only is a pair of complementary elements 100, 200 provided in line with the articulation zones 172, 272 of the secondary webs 170, 270, but additional rows of such complementary elements 100 a, 200 a and 100 b, 200 b are also provided, on either side of the articulation zones 172, 272, respectively. These additional complementary elements 100 a, 200 a and 100 b, 200 b reinforce the assurance of difficult opening by avoiding a change in relative position between the primary webs 160, 260 regardless of the origin of the stress, internal or external.

The two embodiments illustrated in FIGS. 19 and 20 lead to a quasi-impossible opening without damaging the closure device, whether under the pressure inside the bag or in the form of an external opening attempt. Such closure assemblies can be used to equip single-use bags, for example to store securities, bank products or other such products, or any other product, for example all food or household products or their equivalents in a single-use bag.

Alternatively a line of weakness can be provided on a localized zone of the closure devices illustrated in FIGS. 19 and 20, for example at one of the articulation zones 172 or 272, in order to monitor and confine the tear zone, when an opening is forced, in order to clearly visualize that opening. To that end, one may for example provide for elongating at least one of the articulation zones 172, 272 in the form of a rod connecting the external surface of a primary web 160, 260 and the internal surface of a secondary web 170, 270, and at which said line of weakness is provided.

Of course, the present invention is not limited to the embodiments just described, but rather extends to all alternatives according to its spirit.

In particular the set of features previously described respectively with regard to a specific figure can be combined with all of the features illustrated in the other figures.

For example and non-limitingly, each of the alternatives can comprise complementary elements 100, 200 of any type whatsoever (in particular male/female type, hooks, or similar), be connected to the films of a bag or attached on these films, include or not include a film forming opening indicator which must be broken upon the first use, include or not include an operating slide.

In FIG. 21, we have illustrated another alternative embodiment according to the present invention according to which the primary webs 160, 260 are provided with ridges 165, 265 facilitating the gripping and identification of the webs 160 260. Such an arrangement is known by those skilled in the art and will not be described in detail below.

In the appended FIG. 22 we have also shown another alternative embodiment in which one finds, as for all of the embodiments according to the present invention illustrated in FIGS. 6 to 21, two complementary elements 100, 200 coextruded with primary webs 160, 260 and secondary webs 170, 270 designed to be connected to the walls 10, 20 of the bag and which are connected to the primary webs 160, 260 at articulations 172, 272 situated in line with connecting zones of the closure elements 100, 200 on the primary webs 160, 260. However, the embodiment illustrated in FIG. 22 also comprises two additional complementary elements 105, 205, at least one of which, in this case the element 105, is supported by an additional articulated sealing web 107. This additional sealing web 107 is itself connected to one of the primary webs 160, 260, in this case the primary web 160, at a zone 108 not superimposed on the corresponding closure element 105. Furthermore the additional articulated web 107 extends beyond the closure element 105 such that upon engagement of the additional complementary closure elements 105, 205, the end 109 of the articulated web 107 bears on an opposite structure, in this case the opposite primary web 260. The preceding arrangement is according to the patent application filed by the Applicant on Dec. 17, 2008 under No. FR 08 58680. It therefore will not be described in more detail below. This arrangement, which makes it possible to strengthen the sealing of the closure device and of the bag, can in itself be the object of different alternative embodiments, as indicated in application FR 08 58680.

In FIG. 23, we have illustrated a cross-section of a specific embodiment of a closure assembly according, in its principle, to FIGS. 6 and 10. Indeed in FIG. 23 we find an embodiment according to which each primary web 160, 260 supports three arrowhead elements 100, 200 designed to become interlinked with the complementary elements supported by the opposite web. Also provided are extensions toward the outside of the primary webs 160, 260 in the form of sections 164, 264 and secondary webs 170, 270 articulated on the primary webs 160, 260, at articulations 172, 272.

More specifically according to the embodiment illustrated in FIG. 23, the external sections 164, 264 of the primary webs 160, 260 are globally situated in the extension of the secondary webs 170, 270. The primary webs 160, 260 are thus connected to the outer sections 164, 264 via respective at least semi-rigid recesses 166, 266, outwardly oriented from the primary webs 160, 260. The secondary webs 170, 270 are provided with a zone of small thickness forming the articulation 172, 272, near the aforementioned recesses 166, 266. The primary webs 160, 260, the complementary elements 100, 200 supported by them, the secondary webs 170, 270 and the sections 164, 264 are globally symmetrical.

FIG. 24 illustrates an alternative embodiment from FIG. 23 which differs from the latter figure by the fact that according to FIG. 24, the external sections 164, 264 of the primary webs 160, 260 are globally situated in the extension of the primary webs 160, 260 and are at least semi-rigidly connected thereto. The secondary webs 170, 270 are connected to the primary webs 160, 260 via respective flexible recesses 166, 266 outwardly oriented from the primary webs 160, 260. The recesses 166, 266 are advantageously made up here of zones of small thickness forming the articulation 172, 272. The primary webs 160, 260, the complementary elements 100, 200 supported by them, the secondary webs 170, 270 and the sections 164, 264 are again globally symmetrical here.

FIG. 25 illustrates a cross-sectional view of a specific embodiment of a closure assembly according, in its principle, to FIG. 10.

Indeed in FIG. 25 we find an alternative embodiment according to which the primary webs 160, 260 extend on either side of the articulation zones 172, 272 and the closure assembly comprises secondary webs 170, 270 and additional auxiliary webs 190, 290 all flexibly articulated in 172, 272 on the primary webs 160, 260. The secondary webs 170, 270 and the additional auxiliary webs 190, 290 are globally aligned, respectively. Furthermore, a pair of complementary elements 100, 200 is provided in line with the articulation zones 172, 272 of the secondary webs 170, 270, and additional rows of such complementary elements 100 a, 200 a and 100 b, 200 b are also provided, on either side of the articulation zones 172, 272, respectively. These additional rows of complementary elements 100 a, 200 a and 100 b, 200 b reinforce the assurance of difficult opening by avoiding a change of relative position between the primary webs 160, 260 regardless of the origin of the stress, internal or external. The articulation zones 172, 272 are made up of recesses oriented outwardly from the primary webs 160, 260. Here again the primary webs 160, 260, the complementary elements 100, 200 supported by them, the secondary webs 170, 270 and the additional auxiliary webs 190, 290 are globally symmetrical.

In FIGS. 26 and 27 we have illustrated two alternative embodiments which differ from the embodiments illustrated in FIGS. 10 and 20, respectively, by the fact that one of the primary webs 260 is extended in its inner end by a return 292, adapted to overlap the free inner edge of the opposite primary web 160 and thereby strengthen the sealing of the assembly, in closed position. The return 292 is convex toward the inside of the bag.

One will note that several embodiments of closure assemblies according to the present invention are made up of two symmetrical sub-assemblies (see for example FIGS. 10, 13 to 16, 19 to 21, 23 to 25). Such a symmetry offers many advantages. It makes it possible to realize the closure assembly using a single extrusion die and therefore a low cost. It also makes it possible to realize the closure assembly by folding a sub-assembly on itself. It avoids having to differentiate two separate subassemblies, for example including male and female closure elements, respectively.

One will also note that according to the present invention, several complementary closure elements 100 and 200 are provided on each primary web. This arrangement makes it possible to ensure the engagement of the two subassemblies even in case of possible misalignment between the two subassemblies making up the overall closure assembly.

According to other advantageous features of the invention, the closure assembly can:

comprise a film or web forming opening indicator and strengthener

comprise ridges on support webs,

comprise dissymmetrical complementary elements,

comprise an internal branch of a female closure element (200) which is thicker and more rigid than its external element,

be connected on the walls of a bag.

be attached on the walls of a bag.

comprise a web or film forming opening indicator which initially connects the free edges of the internal sections of the primary webs,

comprise a film or web forming opening indicator and sealing strengthener initially connecting the free edges of the external sections of the primary webs,

comprise a web forming opening indicator which includes a weak point, preferably in its median portion, for example in the form of a zone of smaller thickness or a zone in a more fragile material, in order to localize the preferred break line of that web,

comprise additional closure elements, an additional articulated sealing web which supports one of the additional closure elements, said additional web itself being connected to one of the primary webs, at a zone not superimposed on the corresponding additional closure element and which extends beyond this additional closure element such that upon engagement of the additional complementary closure elements, the end of the articulated web bears on an opposite structure, for example the opposite primary web,

be realized fully by extrusion, in thermoplastic material, for example polyethylene- or polypropylene-based,

comprise complementary closure elements which are of the male/female type with complementary shapes, the complementary hooks type or the complementary arrowhead type,

comprise one of the primary webs which supports at least two arrowhead elements adapted to receive, between them, a complementary element supported by the other web,

comprise three levels of complementary elements on the primary webs,

comprise complementary elements supported by the primary webs which are mixed,

comprise each web which supports three arrowhead element designed to become interlinked with the complementary elements supported by the opposite web,

be made up of two symmetrical subassemblies,

include two primary webs which each support three arrowhead elements designed to become interlinked with the complementary elements supported by the opposite web, extensions toward the outside of the primary webs in the form of sections and secondary webs articulated on the primary webs, at articulations, the external sections of the primary webs being globally situated in the extension of the secondary webs, the primary webs being thus connected to the external sections via respective at least semi-rigid recesses, oriented outwardly from the primary webs, and the secondary webs being provided with a zone of smaller thickness forming the articulation, near the recesses,

include two primary webs which each support three arrowhead elements designed to become interlinked with the complementary elements supported by the opposite web, extensions toward the outside of the primary webs in the form of sections and secondary webs articulated on the primary webs, at articulations, the external sections of the primary webs being globally situated in the extension of the primary webs and being at least semi-rigidly connected thereto, the secondary webs being connected to the primary webs via respective flexible recesses oriented outwardly from the primary webs and the recesses being made up of zones of small thickness forming the articulation,

include primary webs which extend on either side of the articulation zone, secondary webs and additional auxiliary webs articulated flexibly on the primary webs, the secondary webs and the additional auxiliary webs being globally aligned, respectively, a pair of complementary elements in line with articulation zones of the secondary webs, additional rows of complementary elements, on either side of the articulation zones, respectively, the articulation zones being made up of recesses oriented outwardly from the primary webs,

comprise one of the primary webs which is extended on its internal end by a return, adapted to overlap the free inside edge of the opposite primary web and thereby strengthen the sealing of the assembly, in closed position. 

1. A closure assembly comprising two complementary elements (100, 200) supported by respective webs, characterized by the fact that said two complementary elements (100, 200) are supported by primary webs (160, 260) coextruded with said two complementary elements (100, 200) and that the closure assembly also comprises secondary webs (170, 270) coextruded with said two complementary elements (100, 200), designed to be connected to the walls (10, 20) of the bag and which are connected to the primary webs (160, 260) at respective articulations (172, 272) formed by extrusion and situated in line with connection zones (102, 202) of a pair of complementary closure elements (100, 200) on the primary webs (160, 260) and additional rows of complementary elements (100 b, 200 b; 100 c, 200 c) supported by the primary webs (160, 260) of at least one side of the articulation zones (172, 272).
 2. The closure assembly according to claim 1, characterized by the fact that said articulations (172, 272) are flexible.
 3. The closure assembly according to claim 1, characterized by the fact that the respective articulations (172, 272) are formed by a narrowing of material.
 4. The closure assembly according to claim 1, characterized by the fact that the respective articulations (172, 272) are formed by or near a recess between the primary webs (160, 260) and the secondary webs (170, 270).
 5. The closure assembly according to claim 1, characterized by the fact that auxiliary opening webs (164, 264) are at least semi-rigidly connected to the primary webs (160, 260), respectively.
 6. The closure assembly according to claim 1, characterized by the fact that the primary webs (160, 260) extend on either side of said connection zones (102, 202), such that the external sections (164, 264) of the primary webs (160, 260) constitute auxiliary opening webs at least semi-rigidly connected to the primary webs (160, 260), respectively, allowing easy opening of the bag from the outside thereof.
 7. The closure assembly according to claim 6, characterized by the fact that the intrinsic rigidity of the external sections (164, 264) of the primary webs (160, 260) and the rigidity of the connection (102, 202) existing between these external sections (164, 264) of the primary webs and the closure elements (100, 200), are greater than the rigidity of the articulation connection (172, 272) defined between the secondary webs (170, 270) and the primary webs (160, 260).
 8. The closure assembly according to claim 1, characterized by the fact that it also comprises an operating slide (300).
 9. The closure assembly according to claim 1, characterized by the fact that the primary webs (160, 260) are interrupted at the articulation zones (172, 272) such that the opening is quasi-impossible from the outside of the bag.
 10. The closure assembly according to claim 1, characterized by the fact that it comprises auxiliary webs (180, 280; 190, 290) oriented toward the outside of the closure assembly and flexibly articulated on the primary webs (160, 260) such that opening is quasi-impossible from the outside of the bag.
 11. The closure assembly according to claim 1, characterized by the fact that the primary webs (160, 260) extend on either side of the articulation zone (172, 272) and the closure assembly comprises secondary webs (170, 270) and additional auxiliary webs (190, 290) all flexibly articulated in (172, 272) on the primary webs (160, 260).
 12. The closure assembly according to claim 1, characterized by the fact that it comprises a line of weakness on a zone localized, for example, at one of the articulation zones (172 or 272), in order to monitor and confine the tear zone, when an opening is forced, in order to clearly visualize that opening.
 13. The closure assembly according to claim 1, characterized by the fact that it comprises a pair of complementary elements (100, 200) in line with the articulation zones (172, 272) of the secondary webs (170, 270), and additional rows of complementary elements (100 a, 200 a; 100 b, 200 b), supported by the primary webs (160, 260) on either side of the articulation zones (172, 272), respectively.
 14. The closure assembly according to claim 13, characterized by the fact that the additional rows of complementary elements (100 a, 200 a; 100 b, 200 b) comprise at least one flange (120, 220; 130), or a pair of male/female type elements or hooks-type elements or velvet/hooks-type elements.
 15. The closure assembly according to claim 1, characterized by the fact that it is provided with a web forming opening indicator (140, 144, 148).
 16. The closure assembly according to claim 1, characterized by the fact that each of the primary webs (160, 260) supports a plurality of complementary elements (100, 200) capable of engaging.
 17. The closure assembly according to claim 1, characterized by the fact that it comprises a first level of complementary elements (100 a, 200 a) in line with the articulation zones (172, 272) of the secondary webs (170, 270) and two additional levels of complementary elements (100 b, 200 b and 100 c, 200 c) of the hooks type, on the inside of the bag in relation to the first level of aforementioned complementary elements (100 a, 200 a).
 18. The closure assembly according to claim 1, characterized by the fact that the primary webs (160, 260) and the complementary elements (100, 200) supported by them are symmetrical.
 19. The closure assembly according to claim 1, characterized by the fact that the primary webs (160, 260) support at least one sealing flange (120, 220, 130).
 20. A bag characterized by the fact that it comprises a closure assembly according to claim
 1. 